Stabilized halogen containing polymers

ABSTRACT

NOVEL COMPOUNDS USEFUL AS STABILIZERS FOR HALOGEN CONTAINING POLYMERS SUCH AS POLYVINYL CHLORIDE ARE REPRESENTED BY THE FORMULA:   (R-CO-S)N-X   WHEREIN R IS A HYDROCARBYL GROUP, N IS AN INTEGER HAVING A VALUE OF FROM 1 TO 2, AND X IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, ALKALI METAL, ALKALINE EARTH METAL, AND ACRYL MOIETIES HAVING A HYDROCARBYL RESIDUE.

United States Patent O 3,574,692 STABILIZED HALOGEN CONTAINING POLYMERS Walter Stamm, Tarrytown, N.Y., assignor t Stautfer Chemical (Iompany, New York, N.Y.

No Drawing. Application Jan. 12, 1967, Ser. No. 608,751, which is a continuation-in-part of application Ser. No. 586,045, Oct. 12, 1966. Divided and this application Aug. 2, 1968, Ser. No. 763,463

lint. Cl. C08h 9/02 US. Cl. 260-399 6 Claims ABSTRACT OF THE DISCLOSURE Novel compounds useful as stabilizers for halogen containing polymers such as polyvinyl chloride are represented by the formula:

wherein R is a hydrocarbyl group, n is an integer having a value of from 1 to 2, and X is selected from the group consisting of hydrogen, alkali metal, alkaline earth metal, and acryl moieties having a hydrocarbyl residue.

This application is a division of application Ser. No. 608,751 filed Jan. 12, 1967, now Pat. No. 3,461,091, which is a continuation in part of patent application U.S. Ser. No. 586,045 filed Oct. '12, 1966, now abandoned.

High molecular weight halogen containing polymeric compositions exhibiting a high degree of stability containing a stabilizing amount of a stabilizing compound having the formula wherein R is a hydrocarbyl group containing from 3 to about 21 carbon atoms, n is an integer having a value of from 1 to 2, X is selected from the group consisting of hydrogen, alkali metal, alkaline earth metal, and acyl moieties having a hydrocarbyl essentially hydrocarbon residue and containing from about 1 to about 17 carbon atoms inclusive. These stabilizers have proven to be particularly effective in the polyvinyl chloride resin compositions. Included among the preferred stabilizers is thiollauric anhydride, thiololeic anhydride, thiolbenzoic anhydride and thiolstearic anhydride. This stabilizing system is one of the few proposed for vinyl type resins which does not contain a heavy metal moiety such as tin as an integral part of the stabilizer. An additionally preferred stabilization system for such resins, include combinations of such materials as zinc stearate and thiolstearic acid. It is similarly preferred that the resins contain a small but effective amount of an epoxidized stabilizer such as an epoxidized fat.

The present invention relates to the stabilization of polymers against degradation and discoloration due to heating. More particularly, it relates to heat stabilization of halogen containing hydrocarbon polymers, especially chlorine containing polymers of vinyl monomers including homopolymers of polyvinyl chloride and polyvinylidene chloride as well as copolymers of each. Still more particularly, the invention relates to the heat stabilization of such polymers employing certain thiol acids and derivatives thereof which are hereinafter defined.

It is well known that chlorovinyl polymers, and in particular polyvinyl chloride, undergo discoloration and degradation at the elevated temperatures required for operations such as molding and product formation. In order to overcome this problem a suitable amount of a heat stabilizing composition is generally blended with plasticized or unplasticized resinous material prior to molding. One suitable component of commercial stabilizing compositions employed widely today is stearic acid or salts thereof. The stearic acid derivatives have found wide acceptance because they exhibit acceptable performance, are readily available at a low cost and are non toxic. Unfortunately, stearicacid and its derivatives are unsuitable for general use at the high processing temperatures required to work the rigid, unplasticized polyvinyl chloride and permit discoloration and degradation after a relatively short period of time even at the lower temperatures (i.e., about 310 F.) required for processing of flexible, plasticized polyvinyl chloride. Other known stabilizers for polyvinyl chloride include the organotin compounds, which because of their unusual heat stabilizing properties set a standard for heat stability which is difficult to equal. However, the organotin compounds have the disadvantage that they are very expensive and toxic, which greatly limits their scope of application.

It is therefore the object of the present invention to overcome and eliminate the deficiencies inherent in the stabilization of halogen containing polymers and to provide improved, heat stabilized polymeric composition in an economically attractive manner.

Another object of the present invention is to provide an improved, heat stabilized composition comprising polyvinyl chloride and polyvinylidene chloride homopolymers as well as copolymers.

Another object is to provide heat stabilized chlorovinyl polymers which are colorless, clear, non-blooming, odorless and non-toxic.

Another object of the present invention is to provide novel, heat stable compositions comprising a chlorovinyl polymer and a thiol acid or suitable derivative thereof.

Another object of the present invention is to provide novel, alkaline earth soaps of a thiol acid useful in the heat stabilization of polyvinyl chloride.

Other objects and advantages inherent in the present invention will become apparent from the following description and disclosure.

The above stated and other objects are generally accomplished in accordance with the present invention by providing a heat stabilized halogen containing polymeric composition containing as a stabilizer an eflective amount of a compound of the type:

wherein R is a hydrocarbyl group consisting essentially of hydrogen and carbon having from 5 to 21 carbon atoms and preferably from 6 to 17 carbon atoms, n equals 1 or 2, and X is selected fromthe group consisting of hydrogen, alkali metal including ammonia, alkaline earth metals and an acyl moiety of the type 0 g RI wherein R is a hydrocarbyl group consisting essentially of hydrogen and carbon containing from about 1 to about 17 carbon atoms inclusive. The term consisting essentially of hydrogen and carbon refers to substituted hydrocarbon moieties containing an occasional or infrequent substituent comprising an element other than hydrogen and carbon, e.g., nitrogen or chlorine which does not materially alter the properties of the hydrocarbon residue, i.e., remains inert, as Well as to purely hydrocarbon moieties. This invention is predicated upon the discovery that the incorporation of, say, 3 percent of a compound defined above in vinyl chloride polymer gives a wholly unexpected improvement in polymer color during heat processing as compared with stearic acid, lauric acid or benzoic acid and their derivatives after processing at elevated temperatures over a-protracted-period of time. In the practice of the present invention it has been found that the incorporation of thiollauric anhydride into plasticized polyvinyl chloride resin in an amount such that the sulfur content of the mixture is as low as 0.1% by weight gives an unexpected improvement in stabilization at high temperatures.

Representative groups of compounds within the scope of the above-identified formula include the aliphatic thiol acids such as the fatty thiol acids, alkali metal soaps of the fatty thiol acids, alkaline earth metal soaps of the fatty thiol acids, as well as the fatty thiolanhydrides; aromatic thiol acids, alkali metal salts of the aromatic thiol acids, alkaline earth salts of the aromatic thiol acids, as well as the aromatic thiol anhydrides.

Representative of specific compounds suitable for use in accordance with the present invention include the thiolcaproic, thiolenanthic, thiolcaprylic, thiolpelargonic, thiolcapric, thiolundecanoic, thiollauric, thioltridecanoic, thiolmyristic, thiolpentadecanoic, thiolpalmitic, thiolmargaric, thiolcarboxylic analogs of so-called neo-acids, thiolstearic, thiolnonadecanoic, thiolarachidic and thiolheneicosanoic acids, thiolnaphthenic acid, thiolbenzoic acid, phenylthiolacetic acid, methylthiolbenzoic acid, tolylthiolacetic acid, naphthalenethiolcarboxylic acids, as Well as the alkali and alkaline earth salts and anhydrides thereof. Compounds containing the same number of carbon atoms as the above but which have unsaturated bonds present, e.g., undecylenic, oleic and thiolcrotonic acids, etc., are likewise suitable.

Representative of preferred specific compounds within such groups include thiolstearic acid, thiolpalmitic acid, thiolversatic acid, thiollauric acid, thiolbenzoic acid, thioltoluic acid, thiolmesitoic acid, zinc thiolstearate, calcium thiolstearate, cadmium thiolstearate, barium thiolstearate, magnesium thiolpalmitate, zinc thiollaurate, cadmium isododecanoate, mixed thiol fatty acid soaps, zinc thioleate, thiolstearic anhydride, stearic palmitic thiolanhydride, thiolbenzoic anhydride, thiollauric anhydride, potassium thiololeate, soaps of the thioltallates, dodecenyl succinic thiolanhydride, thiolphthalic and thioltetrahydrophthalic anhydride, and the like, as well as mixtures of such compounds.

The following compounds are illustrative of the essentially hydrocarbon moieties containing an occasional and infrequent, inert substituent other than hydrogen and carbon: alpha-hydroxythiolstearic acid, 9,10-dihydroxythiolstearic anhydride, zinc 11-aminothiolundecanoate, nitro and chlorothiolbenzoic anhydrides.

As indicated above, compounds of the type set forth above are useful in improving the thermal stability of halogen containing polymers including homopolymers as well as copolymers produced from vinyl halide and vinylidene halide monomers. The compounds of the type set out above are particularly useful in stabilizing halo vinyl polymers. The term halo vinyl polymer as employed herein is intended to mean a polymer produced from a monomeric material of the type:

where one or more Y represents halogen, preferably chlorine or bromine, but including fluorine and iodine, covalently bonded to a carbon and the remaining Y or Ys represent a hydrocarbon residue or hydrogen. It is to be understood that the stabilizer compounds of the present invention are similarly useful in inhibiting deterioration of post-halogenated polymers such as hydrocarbon polymers chlorinated after polymerization. Representative copolymeric compositions in which the stabilizer compounds of the present invention are useful include, e.g., copolymers of vinyl chloride or vinylidene chloride with themselves or with vinyl carboxylate esters, e.g., vinyl acetate and vinyl stearate, vinyl ethers, e.g.,

methyl vinyl ether, ethylene, propylene, styrene, maleic and fumaric acids. The stabilizer compounds of the prescnt invention are useful in rigid, unplasticized halovinyl polymers and copolymers as well as plasticized materials. In particular, these compounds are useful in rigid polyvinyl chloride as well as in such polymers containing a plasticizer such as dioctyl phthalate, octyl diphenyl phosphate. Such plasticizers are generally present in an eifective amount which is usually between 10 and 60%.

While the stabilizer compounds in accordance with those of the present invention exhibit marked improvement over closely related compounds in the prior art when employed alone, or in various combinations thereof, it is understood that the compounds of the present invention can be even more advantageously employed in combination with co-stabilizing additives known in the art which include, for example, chemical compounds of the type: organic phosphites, metallic soaps such as calcium or zinc stearate, fatty acids such as stearic acid, phenolic compounds including substituted phenols, barium or cadmium phenolates, phosphinates, phosphonates, mercaptides and sulfides, epoxidized fatty oils, episulfides and epoxides, indoles, lead soaps, including lead naphthenates, polyols, such as sorbitol or pentaerythritol, esters of aminocrotonic acid, dialkyltin carboxylates or mercaptides, alkylstannoic acids, urea or thiourea derivatives, as well as other additives known in the art of halovinyl polymers stabilization.

. It is apparent that the percentage of the fatty thiol compound of the present invention which must be employed in making satisfactory heat stabilized compositions of the present invention in order to achieve the satisfactory improvement in heat stability, will vary over a wide range, depending upon the particular halovinyl polymer in which it is employed, the particular need for stabilization, the particular end use of the resin, the presence of plasticizing or other co-stabilizing additive materials, as well as the time and temperature processing requirements in making a suitable final product. The presence of between about 0.01% and about 10% by weight of the stabilizer compound of the present invention will be sufficient for most applications, although the preferable range is between about 1% and about 5% of said compound on a Weight basis.

The thiol acids and anhydrides useful in the present invention can be prepared in accordance with procedures known in the literature as well as from the novel procedures hereinafter specified. Thiolstearic acid, for example, can be prepared from stearoyl chloride and hydrogen sulfide as well as from stearoyl chloride and alkali or alkaline earth salts ofhydrogen sulfide. In the practice of the present invention, thiolstearic acid (.M.P. 37-41 C). has been prepared from stearoyl chloride and hydrogen sulfide in 96 percent yield employing pyridine as an HCl acceptor. The preparation of certainother thiol acids, e.g., thiolmyristic, thiolbenzoic, as -well as thiolpalmitic acids has likewise been reported in the literature. They can also be obtained by cleavage of acid anhydrides with hydrogen sulfide. In general, the organic thiol acids are practically colorless at room temperature.

It is contemplated that thiol acids can be produced in accordance with two separate, novel and useful processes as follows. Firstly, the production of such acids' is contemplated by the reaction of the desired carboxylic acid, e.g., decanoic acid with phosphorus pentasulfide (P 8 to produce the corresponding thiol acid, e.g., thioldecanoic acid. The .thiol acid is then separated from side products, e.g., dithiolacids, remaining carboxylic acid and phosphorus pentasulfide, for example, by distillation. Another contemplated process route involves the cleavage of fats or other esters of fatty acids employing either hydrogen sulfide under an elevated pressure in the presence of catalysts or salts of hydrogen sulfide. Hydrogen sulfide pressure in the range of from 100 to 1000 p.s.i. arebelieved to be suitable for this purpose. The reaction is represented formulistically below with a glyceride, or fat, wherein R represents a suitable aliphatic hydrocarbon moiety hereinbefore defined:

6 EXAMPLE 3 Barium thiolstearate To the slurry of 36 grams of thiolstearic acid in 500 milliliters of ethanol was added 72 grams of a 77% .g H 3H2S R. CH2OH 5 pure KOH in ethanol. After 30 minutes a hot, 50% aque- R CO O CH2 OH ous ethanol solution containing 31.6 grams of barium nitrate was added to the hot, agitated potassium thiol- CHQOH stearate solution. After minutes the hot reacting mixture was filtered and the filtrate cooled. A crystalline readily available in commerce at low cost, e.g. tallow yleld' It I. Washed wlth hot Water and dned Over P205; fats. M.P. 162 -166 C.

The alkaline earth metal soaps of thiol acids, in par- EXAMPLE 4 ticular, the respective zinc, cadmium, calcium, and barium Thiolstearic anhydride soaps of thiolstearic acid are new and useful compounds discovered in the practice of the present invention. It has grams (0066 111016) P thlolsteanc 301d 111 50 been found that the soaps useful in the present invention mlnlhters of carbon tetrachlorfie are added grams can be prepared, e.g., by metathetical exchange reactions mole) of stearoyl chlorlde d drops of Py between a suitable alkali thiolstearate salt and a salt of an fllne at After one hour py l hydfochlofldfi alkaline earth metaL The Soaps can also be produced by is removed by filtration, and the filtrate is evaporated to the reaction of alkaline earth oxides, acetates, carbonates, Y F The f' solld grams; -2 for example, with fatty thiol acids. Examples of the preprecrystanl? from heptane: 78490 C; Yleld aration of these novel compounds as well as the prepara- Practlcauy quantltatlve- The compound has a Sharp band tion of thiolstearic anhydride and thiolbenzoic anhydride 111 the LR at 7 p d analyzes correctly. are presented be10w The heat stab1hzed polymeric materials of the present invention can be produced by admixing a suitable amount EXAMPLE of the thiol compound of the present invention and a Zi thi l t t suitable hallogen cogtainilng resin,heg demulsiorli1 or sutst;

. pension p0 ymerize p0 yviny c ori e, toget er wi Misti.ttfiliattimiiid12Tittitiifitit. .1529 33 5313 3 3;; i gi fg g f fg g g ggggg u 5 g figf zig gs gg g ggi g lfi g resulting blend can then be formed into useful end prodslurry was then warmed up to 50 C. After 30 minutes ucts by -known methods mgludlilg extruslon 13.6 grams (0 101 mole) of anhydrous zinc chloride was 35 calendermg o? vanous Sheet lormmg operatl9ns' added dissolved in 300 milliliters of alcohol The re- Thsa-fonowmg examples are presented to Imus-gate the action mixture was warmed p to 70 C. for minutes surpnsmglyamproved performance of the stabilizers of and then quickly filtered while hot. Upon cooling about f g g i is i i i 78 grams (approximately 60% of theory) of zinc thiol- 40 i zg ggg fi fi? own m e 30 vmy Po ymer stearate crystallized out. More product was obtained from the mother liquor. The melting point of pure zinc EXAMPLE 5 thwlstearate was 92 95 C- The heat stabilized polyvinyl chloride compositions EXAMPLE 2 set forth in Table 1, below, were formulated on the follow basis: Geon 103 EP (homopolymer of polyvinyl Calclum thlolstearate chloride), 100 parts; dioctyl phthalate (plasticizer), 30 To the slurry of grams (0.167 mole) of thiolstearic parts; parts stabilizer compound indicated in Table I. acid in "300' milliliters of ethanol was added 9.4 grams The various formulations were blended and banded to (0.167 mole) of KOH dissolved in ethanol. After 15 50 obtain homogeneous blends and then subjected to a conminutes 9.3 grams (0.084 mole) of anhydrous calcium ventional milling test to determine dynamic heat stability chloride, also dissolved in ethanol, was added with p y g mill Conditions as fOHOWSI front I011, 30 -P' stirring. After one hour the crude solution was filtered 310 F-; T681" T011, 42 f.p.m., 315 F.; nip setting, 0.035 and ethanol removed by distillation. The re idue wa inch. Samples were taken at 10 minute intervals during carefully washed with acetone, yielding 31 grams of calcontinuous milling and the resulting data relating to cium thiolstearate; M.P. 108-111 C. discoloration are presented in Table 1, following.

TABLE I Color at end of milling period, minute Stabilizer Initial 10 20 30 40 50 Zinc stearate (2 parts) thiol- White. White. Light Light Light Light Light Black.

stearic acid (2 parts). brown. brown. brown. brown. brown. Zinc thiolstearate (3 parts) .do .do...-. White .do Lilght Brown- Brown. Browm Brown- Brown.

rown. Zinc stearate (3 arts) ..do. Black spo s. Thiostearic anhydride (3 parts) ..d0..... White... White-.. White White....- White White-.." Light Light Light yellow. yellow. brown. Thiostearic acid (3 parts) ....do .110 do ..do.. ....do ..do.-..... Light Light Light D0. brown. brown. brown. Do. Stearic acid (3 parts) ..do..... Brown.. D%rk rown. Calcium thlolstearate (3 parts) ..do..-.- White... Grey Grey Grey Light Light Light Light Light brown. brown. brown. brown. brown. Calcium stearate (3 parts) .do...-. Grey.-. Lilght Brown- Brown. Brown. Brown. Brown. Brown. Brown.

rown.

1 Dark brown at minutes. 3 Failure in less than 10 minutes.

3 Brown at about minutes; dark brown about 200 minutes. 4 Failure in less than 20 minutes.

8 The following further observations were made during chloride Were slowly added to the reactor through the these experimentations: dropping funnel. The addition was completed in about 1) No odor was noticed during processing of the 30 minutes, and the reaction was brought to completion thiol compounds at 315 F. by stirring the mixture for about four hours at reflux (2) The stearic acid sample showed color after five temperature. A small amount of pentane (about 20 milliminutes and failed entirely after twenty minutes whereas liters) was then added to the solution which was cooled thiolstearic acid showed only a very gradual color develdown to room temperature. Thiollauric anhydride crysopment over a total period of 240 minutes. The samples tallized out in good yield and high purity. Melting point were practically colorless through 50 minutes and did not 52 -54 C. become brown until after about 140 minutes of proc- EXAMPLE 8 essing.

(3) Thiolstearic, thiollauric and thiolbenzoic anhy- Preparatlon of thlololelc anhydride dride stabilized resins stayed essentially colorless through Molar quantities of thiololeic acid and oleoyl Chloride were reacted under conditions practically identical to 120 minutes.

(4) PVC resins containing thiollauric anhydride as :Ehose p y in lg Thiololeic anhydride Was stabilizer showed better clarity than those stabilized with Isolated as a Colorless 011 Which Was analytically P thiolstearic anhydrida without distillation.

(15) The zinc stearate sample showed large black spots EXAM LE 9 in less than 5 minutes whereas the zinc thiolstearate showed no color for about 30 minutes and did not become 'Evaluatlon of Stablhzatlon efiect dark brown until about 120 minutes. The stabilization eflects of:

(6) It was found that zinc thiolstearate as well as Thiolbenzoic anhydride thiolstearic acid used alone showed bloom or migra- Thiollauric anhydride and tion to the surface of the resin, whereas when used in Thiololeic anhydride combination with each other the resulting material unexpectedly did not bloom, but rather resulted in a clear Were evaluated as fOHOWSI in, Three grams of each of the stabilizer candidate were (7) When zinc stearate or thiolstearic acid were inblended respectively With 100 grams of Polyvinyl chloride resin and grams of dioctyl phthalate plasticizer. Each blend Was milled at a temperature of 315 F. Samples of resin were removed from the hot mill at ten minute intervals and examined. The results of this evalucorporated into resins separately, the films produced were cloudy whereas the combination of zinc stearate and 30 thiolstearic acid in the resin unexpectedly gave clear plastic films which Were also odorless.

(8) Resins containing about 5% of epoxidized fats in ation are shown in Table II, following:

TABLE II Color at end of timed milling period, minutes Stabilizer Initial 10 20 30 50 60 70 80 90 Thiobenzoic anhydride Wliite and White-.. White... White-.. White... White--. White..." White... Liglfit h Yellowish 0 ye owis Thiollauric anhydride... o d do Ye1lowish Do. Thiololeic anhydride... do do do do do .-d0 Light Light Yellow Dark yellow. yellow. yellow.

addition to the thiol compounds of this invention showed EXAMPLE 10 further substantially increased stability as evidenced by improved color.

(9) Related thiol acid esters such as butylthiolstearate provided no significant stabilization.

Preparation of thiolstearic/thiolbenzoic anhydride One mole of thiolstearic acid is charged to a reaction vessel containing 500 milliliters of benzene as solvent.

EXAMPLE 6 one mole of benzoyl chloride is added and the reaction nh d is heated to reflux and maintained at reflux for approxi- P161? ratlon of thlolbenzolc y n e mately 3 hours. The product is recovered by removal of In 300 milliliters of hot water was dissolved 140 grams the solvent of 60% aqueous sodium sulfide- To this Solution were The mixed thiolstearic/thiolbenzoic acid anhydride added three grams of a fommercial Wetting agentl and provides excellent stability and compatibility With PVC 90 grams of disodiuni acid phosphate hydrate as butter. resins After cooling the mixture to 0 C., 280 grams of benzoyl EXAMPLE 11 chloride were added with continued stirring of the mixture- The batch temperature was kept below 150 Preparation of thiolstearic/thiolacetic anhydride throughout. Thiolbenzoic anhydride was filtered from the reaction mixture, washed with cold water and dried This wmpound is prepared in a manner identical to under Vacuum at The P Q had afneltmg P that of Example 10 except that one mole of acetyl chlo- Of and Was recovered 111 96% yleldride is used in place of the benzoyl chloride.

What is claimed is: EXAMPLE 7 1. Compounds of the type: Preparation of thiollauric anhydride In a reaction flask provided With a stirrer, dropping funnel and an efficient cold water condenser were diso s solved 21.6 grams (0.1 mole) of thiollauric acid in 50 H j ll milliliters of benzene. A constant stream of dry nitrogen was sparged through the agitated solution which was warmed u to 60 C. Then 22 rams of distilled lauroyl p g wherein R and R are hydrocarbyl groups selected from Aeiosol AT trademark of American Cyanamid. the class consisting of alkyl and aromatic radicals having from 5 to 21 carbon atoms, and X is an alkaline References Cited earth metal radical.

2- Compounds of claim 1 in Which R and R are alkyl FOREIGN PATENTS groups having from 6 to 17 carbon atoms inclusive. 1 144:682 10/1967 France 260399 ra(112.6gompounds of claim 2 in which X is a calcium 5 OTHER REFERENCES 4. Compounds of claim 2 in which X is a barium Chemical Abstracts (1959), vol. 53, pars. 22, 759(f). radical.

5. Compounds of claim 2 in which X is a zinc radical. ELBBRT ROBERTS, Primary Examiner 6. Compounds of claim 1 in which R and R are aro- 10 matic groups having from 6 to 17 carbon atoms inclusive. 26023 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3,574,6 Dated April 13, 1971 Patent No.

Walter Stamm lnventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 24, "acryl" should read acyl Colu1 2, line 49, "wherein R should read wherein R line "including ammonia" should read including ammonium Column 6, line 9, "hot reacting" should read hot reaction Columns 5 and 6 Table 1, column 90 should appear as shown beI Black Brown Blank Light Brown Light Brown Blank (omit second "Do") etc Signed and sealed this 21st day of September 1971 (SEAL) Attest:

EDWARD M. FLETCHER,JR. ROBERT GOTTSCHLAK Attesting Officer Acting Commissioner of Pa 

